I think that that is because Microsoft would probably only create a Walled Garden. What's the chance they will allow a system where anyone can host their own re

I think that that is because Microsoft would probably only create a Walled Garden. What's the chance they will allow a system where anyone can host their own repository, and add/remove them as a user? EEE doesn't seem applicable here, because there's nothing to embrace and extend. It's problem that has to be solved for scratch.